This application claims priority to Japanese patent application serial number 2001-281783, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to die-casting systems and machines, into which molten materials are injected into dies under high pressure to cast products. In particular, the present invention relates to techniques for withdrawing cores from dies, which cores are disposed within the dies during a die-casting operation.
2. Description of the Related Art
Apparatus for withdrawing a core from die-casting machines are known. For example, Japanese Laid-Open Patent Publication No. 5-200488 teaches a die-casting machine that includes a core withdrawing apparatus, which is mounted on a die. The core withdrawing apparatus includes a cylinder device that is coupled to a core via a link mechanism in order to withdraw the core.
However, because the core withdrawing apparatus is mounted on the die in the known die-casting machine, the die naturally has a large size. In addition, the core withdrawing apparatus extends from an outer surface of the die as an appendix or projection. In particular, in the case of die-casting systems that exchange two or more dies (i.e., the casting operation is performed by using two dies that are alternately transferred to and from a single die-casting unit in order to increase productivity), large-size dies and a core withdrawing apparatus extending from the die as an appendix are disadvantageous when the die is transferred into and out of the die-casting unit.
Therefore, it is one object of the present invention to teach improved die-casting systems and machines that can minimize the size of dies.
According to one aspect of the present teachings, die-casting systems are taught that may include one or more core withdrawing device(s). The core withdrawing device(s) may be operable to withdraw a core(s) that is disposed within the die. The core withdrawing device may be arranged and configured independently of the die.
Therefore, the die may be constructed without the core withdrawing device, so that the die may have a small size. As a result, the die can be more easily disassembled for maintenance work. In addition, manufacturing and operation costs may be reduced, because it is not necessary to provide a core withdrawing apparatus for each die.
According to another aspect of the present teachings, the core withdrawing device(s) may be mounted on a support frame. Further, the die may be movable relative to the support frame. According to another aspect of the present teachings, the core withdrawing device(s) may automatically engage the core when the die is opened.
According to another aspect of the present teachings, methods for withdrawing a core(s) from a die in a die-casting system are taught, in particular for a core(s) that is disposed within the die. The methods may comprise withdrawing the core(s) from the die using a core withdrawing device(s) after a casting operation has been completed. The core withdrawing device(s) is preferably independent of the die.
Additional objects, features and advantages of the present invention will be readily understood after reading the following detailed description together with the claims and the accompanying drawings.